CN107995958B

CN107995958B - Driving method of liquid crystal display device with switchable wide and narrow viewing angles

Info

Publication number: CN107995958B
Application number: CN201780002179.6A
Authority: CN
Inventors: 钟德镇; 廖家德; 苏子芳; 姜丽梅
Original assignee: InfoVision Optoelectronics Kunshan Co Ltd
Current assignee: InfoVision Optoelectronics Kunshan Co Ltd
Priority date: 2017-07-04
Filing date: 2017-07-04
Publication date: 2021-01-15
Anticipated expiration: 2037-07-04
Also published as: CN107995958A; US20200159050A1; WO2019006665A1; US11187928B2

Abstract

In a first visual angle mode, applying a direct current common voltage to a common electrode, and applying voltage signals to a first bias electrode and a second bias electrode to ensure that voltage differences between the first bias electrode and the common electrode and between the second bias electrode and the common electrode are smaller than a preset value; under a second visual angle mode, applying a direct current public voltage to the public electrode, applying a first alternating current voltage to the first bias electrode, and applying a second alternating current voltage to the second bias electrode, so that voltage differences between the first bias electrode and the public electrode and between the second bias electrode and the public electrode are both larger than a preset value; and in a second viewing angle mode, the pixel units covered by each first electrode strip of the first bias electrode are alternately positive and negative with different polarities, and the pixel units covered by each second electrode strip of the second bias electrode are alternately positive and negative with different polarities.

Description

Driving method of liquid crystal display device with switchable wide and narrow viewing angles

Technical Field

The present invention relates to the field of liquid crystal display technologies, and in particular, to a driving method of a liquid crystal display device with switchable wide and narrow viewing angles.

Background

A Liquid Crystal Display (LCD) has advantages of good picture quality, small size, light weight, low driving voltage, low power consumption, no radiation, and relatively low manufacturing cost, and is dominant in the field of flat panel displays.

The current liquid crystal display device gradually develops towards a wide viewing angle, no matter a mobile phone terminal application, a desktop display or a notebook computer, but in addition to the requirement of a wide viewing angle, in many occasions, the display device is required to have a function of switching between a wide viewing angle and a narrow viewing angle.

At present, the switching between the wide viewing angle and the narrow viewing angle is generally realized by the shielding function of the shutter, which requires an additional shielding film outside the display device, and is inconvenient to use.

Recently, it has been proposed to apply a vertical electric field to liquid crystal molecules by using a viewing angle control electrode on the color filter substrate (CF) side to switch between a wide viewing angle and a narrow viewing angle. Referring to fig. 1 and 2, the lcd device includes an upper substrate 11, a lower substrate 12, and a liquid crystal layer 13 disposed between the upper substrate 11 and the lower substrate 12, wherein a viewing angle control electrode 111 is disposed on the upper substrate 11. As shown in fig. 1, in the wide viewing angle display, the viewing angle control electrode 111 on the upper substrate 11 does not apply a voltage, and the liquid crystal display device realizes the wide viewing angle display. As shown in fig. 2, when a narrow viewing angle display is required, the viewing angle control electrode 111 on the upper substrate 11 is energized, the liquid crystal molecules in the liquid crystal layer 13 will tilt due to the vertical electric field E (as shown by the arrow in the figure), and the contrast of the liquid crystal display device is reduced due to light leakage, thereby finally realizing a narrow viewing angle.

However, in the existing wide and narrow viewing angle switching architecture, the collocated viewing angle control electrode is a transparent conductive electrode, and the resistance value of the transparent conductive electrode is large, so that the viewing angle control electrode can face large impedance and load in signal transmission, which causes distortion of voltage waveform transmitted on the viewing angle control electrode, and the waveform distortion can cause the viewing angle control electrode and the corresponding pixel electrode and common electrode to generate different voltage differences. If the viewing angle control electrode adopts a patterned electrode strip structure, and each electrode strip is arranged along the horizontal direction or the vertical direction, the voltage difference between the electrode strips in each row or each column direction under the whole picture and the pixel electrode and the common electrode acts, so that the whole column or the whole row displays brightness and darkness, and the problem of vertical stripes or horizontal stripes is caused under the narrow viewing angle mode.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a driving method for a liquid crystal display device with switchable wide and narrow viewing angles, which can switch between two modes of wide and narrow viewing angles and solve the problem of vertical stripes or horizontal stripes of the conventional structure.

The invention provides a driving method of a liquid crystal display device with switchable wide and narrow visual angles, which comprises a lower substrate, an upper substrate and a liquid crystal layer positioned between the lower substrate and the upper substrate; the lower substrate is provided with a scanning line, a data line, a pixel electrode and a common electrode, and a plurality of pixel units are formed by mutually insulating, crossing and limiting a plurality of scanning lines and a plurality of data lines; the upper substrate is provided with a first bias electrode and a second bias electrode, the first bias electrode comprises a plurality of first electrode strips which are electrically connected together, the second bias electrode comprises a plurality of second electrode strips which are electrically connected together, and the plurality of first electrode strips and the plurality of second electrode strips are mutually inserted and matched in an interdigital manner, and the driving method comprises the following steps:

in a first viewing angle mode, applying a direct current common voltage to the common electrode, outputting a driving voltage to each pixel unit, realizing gray scale display through different voltage values, and applying voltage signals to the first bias electrode and the second bias electrode to enable a voltage difference between the first bias electrode and the common electrode and a voltage difference between the second bias electrode and the common electrode to be smaller than a preset value;

under a second visual angle mode, applying a direct current common voltage to the common electrode, outputting a driving voltage to each pixel unit, realizing gray scale display through different voltage values, applying a first alternating voltage to the first bias electrode, and applying a second alternating voltage to the second bias electrode, so that voltage differences between the first bias electrode and the common electrode and between the second bias electrode and the common electrode are both larger than a preset value;

in a second viewing angle mode, each pixel unit covered by each first electrode strip of the first bias electrode presents alternating positive and negative different polarities, and each pixel unit covered by each second electrode strip of the second bias electrode presents alternating positive and negative different polarities;

in a second viewing angle mode, the polarities of the driving voltages output to the pixel units are inverted in a row manner, the first alternating voltage applied to the first bias electrode and the second alternating voltage applied to the second bias electrode have opposite polarities with respect to the direct-current common voltage on the common electrode, the adjacent pixel units in the same row are represented by bright and dark, for all the pixel units, the other pixel units adjacent to the brighter pixel unit are represented by relatively dark, and the other pixel units adjacent to the darker pixel unit are represented by relatively bright; or, the plurality of first electrode stripes and the plurality of second electrode stripes extend along a vertical direction, in a second viewing angle mode, polarities of driving voltages output to the pixel units are inverted in a row, a first alternating voltage applied to the first bias electrode and a second alternating voltage applied to the second bias electrode have opposite polarities with respect to a direct current common voltage on the common electrode, the adjacent pixel units in the same row are represented by bright and dark, for all the pixel units, the other pixel units adjacent to the brighter pixel unit among the pixel units are represented by relatively dark, and the other pixel units adjacent to the darker pixel unit among the pixel units are represented by relatively bright.

Further, when the polarity of the driving voltage output to each pixel unit is column-inverted or row-inverted, in the second viewing angle mode, the first ac voltage applied to the first bias electrode and the second ac voltage applied to the second bias electrode are both square waves and mirror images with respect to the dc common voltage on the common electrode.

Further, in the second viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode and the driving frequency of the second ac voltage applied to the second bias electrode are 1/2 of the frame rate of the liquid crystal display device, and the polarity of the driving voltage output to each pixel unit is inverted every two frames.

Further, in the second viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode and the driving frequency of the second ac voltage applied to the second bias electrode are 1/4 of the frame frequency of the liquid crystal display device, and the polarity of the driving voltage output to each pixel unit is inverted once per frame or once per four frames.

Further, in a first viewing angle mode, a dc voltage signal equal to the dc common voltage of the common electrode is applied to both the first bias electrode and the second bias electrode, so that the voltage difference between the first bias electrode and the common electrode and between the second bias electrode and the common electrode is zero.

Further, the liquid crystal layer uses positive liquid crystal molecules, the first viewing angle mode is a wide viewing angle mode, and the second viewing angle mode is a narrow viewing angle mode.

Further, the liquid crystal layer uses negative liquid crystal molecules, and the first viewing angle mode is a narrow viewing angle mode and the second viewing angle mode is a wide viewing angle mode.

Furthermore, the upper substrate is further provided with a plurality of first metal strips and a plurality of second metal strips, the plurality of first metal strips are parallel to the plurality of first electrode strips and are respectively in conductive connection with the plurality of first electrode strips, and the plurality of second metal strips are parallel to the plurality of second electrode strips and are respectively in conductive connection with the plurality of second electrode strips.

Furthermore, the liquid crystal display device is provided with a visual angle switching key for switching different visual angle modes of the liquid crystal display device.

According to the driving method of the liquid crystal display device with switchable wide and narrow viewing angles, provided by the embodiment of the invention, the two modes of the wide and narrow viewing angles can be switched by the arrangement mode and the applied signal of the bias electrode of the upper substrate and the inversion driving mode of the lower substrate, and meanwhile, the problems of vertical stripes and horizontal stripes in the traditional framework are solved, and the display image quality of the display device is improved.

Brief description of the drawings

Fig. 1 is a partial cross-sectional view of a conventional liquid crystal display device at a wide viewing angle.

Fig. 2 is a partial cross-sectional view of the liquid crystal display device of fig. 1 at a narrow viewing angle.

Fig. 3 is a schematic circuit diagram of a liquid crystal display device according to a first embodiment of the invention.

Fig. 4 is a schematic plan view of the first bias electrode and the second bias electrode in fig. 3.

Fig. 5 is a schematic cross-sectional view of the liquid crystal display device of fig. 3 taken along line a-a.

Fig. 6 is a schematic cross-sectional view of the liquid crystal display device of fig. 3 at a narrow viewing angle.

Fig. 7 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of the image in the liquid crystal display device of fig. 3 at a narrow viewing angle.

Fig. 8 is similar to fig. 7, but the voltage difference between the first bias electrode, the second bias electrode and each pixel electrode is represented by a numerical value in each pixel unit.

FIG. 9 is a schematic plan view of the first and second bias electrodes of the LCD device according to the second embodiment of the present invention.

Fig. 10 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the second embodiment of the invention.

Fig. 11 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the third embodiment of the invention.

Fig. 12 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the fourth embodiment of the invention.

Fig. 13 is a schematic diagram illustrating a fifth embodiment of the present invention in which a first bias electrode and a second bias electrode of an lcd device are used in combination with a pixel unit for polarity inversion.

Fig. 14 is a schematic diagram illustrating a configuration of a first bias electrode and a second bias electrode of an lcd device according to a sixth embodiment of the present invention and a polarity inversion of a pixel unit.

Fig. 15 is a schematic diagram of polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the seventh embodiment of the invention.

Fig. 16 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the eighth embodiment of the invention.

Fig. 17 is a schematic diagram of polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the ninth embodiment of the invention.

Fig. 18 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the tenth embodiment of the invention.

Fig. 19 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the eleventh embodiment of the invention.

Fig. 20 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the twelfth embodiment of the invention.

Fig. 21 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the thirteenth embodiment of the invention.

Fig. 22 is a schematic diagram illustrating polarity inversion between voltage signals applied to the first bias electrode and the second bias electrode and the pixel unit in different frames of a picture in the liquid crystal display device according to the fourteenth embodiment of the invention.

FIG. 23 is a schematic plan view of a liquid crystal display device in a fifteenth embodiment of the present invention.

Fig. 24a to 24d are schematic views of different cross-sectional structures of the lcd device of fig. 23 along the line B-B.

FIG. 25 is a schematic plan view of a liquid crystal display device according to a sixteenth embodiment of the present invention.

Fig. 26a to 26d are schematic views of different cross-sectional structures of the lcd device of fig. 25 along the line C-C.

FIG. 27 is a partial cross-sectional view of a liquid crystal display device in a seventeenth embodiment of the present invention.

Fig. 28 is a schematic cross-sectional view of the liquid crystal display device of fig. 27 at a wide viewing angle.

FIGS. 29a and 29b are schematic plan views of a liquid crystal display device in an eighteenth embodiment of the present invention.

Preferred embodiments of the invention

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

The invention provides a driving method of a liquid crystal display device with switchable wide and narrow visual angles, which realizes the switching of the wide and narrow visual angle modes by the arrangement mode and the application signal of a bias electrode of an upper substrate and the inversion driving mode of a lower substrate, solves the problems of vertical stripes and horizontal stripes in the traditional framework and improves the display image quality of the display device.

[ first embodiment ]

Referring to fig. 3 to 5, the liquid crystal display device with switchable wide and narrow viewing angles according to the first embodiment of the present invention includes a display panel 10, where the display panel 10 includes a lower substrate 20, an upper substrate 30 disposed opposite to the lower substrate 20, and a liquid crystal layer 40 disposed between the lower substrate 20 and the upper substrate 30. The lower substrate 20 may be a thin film transistor array substrate (i.e., an array substrate), and the upper substrate 30 may be a color filter substrate (i.e., a color filter substrate).

The lower substrate 20 is provided with a scan line 21, a data line 22, a switching element 23, a pixel electrode 24, and a common electrode 25 on a side facing the liquid crystal layer 40, but the present invention is not limited thereto. The switching element 23 is, for example, a Thin Film Transistor (TFT). The lower substrate 20 is defined by a plurality of scan lines 21 and a plurality of data lines 22 crossing each other in an insulated manner to form a plurality of pixel units arranged in an array. Each pixel unit is provided with a switching element 23 and a pixel electrode 24, and the pixel electrode 24 is connected to the scanning line 21 and the data line 22 through the switching element 23. Each switching element 23 includes a gate electrode electrically connected to the corresponding scan line 21, an active layer, a source electrode electrically connected to the corresponding data line 22, and a drain electrode electrically connected to the corresponding pixel electrode 24.

It is understood that the lower substrate 20 may be further provided with at least one insulating layer or planarization layer to insulate adjacent electrodes or traces from each other or to planarize the inner side of the lower substrate 20.

In this embodiment, the common electrode 25 is formed on the lower substrate 20, the common electrode 25 and the pixel electrode 24 are located on different layers with the insulating layer 26 interposed therebetween, and the pixel electrode 24 is located above the common electrode 25, i.e., the pixel electrode 24 is closer to the liquid crystal layer 40 than the common electrode 25. In this case, the liquid crystal display device is of Fringe Field Switching (FFS) type. In the liquid crystal display device, during normal display, a fringe electric field is generated between the common electrode 25 and the pixel electrode 24, and liquid crystal molecules are rotated in a plane substantially parallel to the substrate to obtain a wide viewing angle.

In other embodiments, the common electrode 25 and the pixel electrode 24 may be located on the same layer on the lower substrate 20, In which case the common electrode 25 and the pixel electrode 24 may be respectively made into a comb-like structure and mutually inserted and matched, and In which case the liquid crystal display device is an In-Plane Switching (IPS) type. In the liquid crystal display device, during normal display, a planar electric field is generated between the common electrode 25 and the pixel electrode 24, and liquid crystal molecules are rotated in a plane substantially parallel to the substrate to obtain a wide viewing angle.

The upper substrate 30 is provided with a Black Matrix (BM)31, a color resist layer 32, a first bias electrode 33, and a second bias electrode 34 on a side facing the liquid crystal layer 40, but the present invention is not limited thereto. The color-resist layer 32 is, for example, R, G, B color resist. In this embodiment, the color resist layer 32 and the black matrix 31 are provided on the inner surface of the upper substrate 30 on the side facing the liquid crystal layer 40, and other film layer structures are provided on the color resist layer 32 and the black matrix 31.

The first bias electrode 33 and the second bias electrode 34 are transparent conductive electrodes. The first bias electrode 33 includes a plurality of first electrode strips 331 spaced apart from each other in parallel and electrically connected together, and the second bias electrode 34 includes a plurality of second electrode strips 341 spaced apart from each other in parallel and electrically connected together, and the plurality of first electrode strips 331 and the plurality of second electrode strips 341 are interdigitated and fitted to each other.

In this embodiment, the plurality of first electrode stripes 331 and the plurality of second electrode stripes 341 both extend along the horizontal direction, i.e., both extend along the scan line 21 direction. The first electrode stripes 331 respectively cover the pixel cells in the odd-numbered rows (i.e.,

rows

1, 3, 5, … …), and the second electrode stripes 341 respectively cover the pixel cells in the even-numbered rows (i.e.,

rows

2, 4, 6, … …).

Further, the first bias electrode 33 further includes a first common conductive strip 332 electrically connected to the plurality of first electrode strips 331, and the second bias electrode 34 further includes a second common conductive strip 342 electrically connected to the plurality of second electrode strips 341. The plurality of first electrode stripes 331 and the plurality of second electrode stripes 341 are located in an effective display area (not shown) of the display panel 10, and the first common conductive stripes 332 and the second common conductive stripes 342 are located in a non-display area (not shown) of the display panel 10.

It is understood that the upper substrate 30 may also be provided with at least one insulating layer or planarization layer to insulate adjacent electrodes or traces from each other or to planarize the inner side of the upper substrate 30.

In this embodiment, the upper substrate 30 is further provided with a first planarization layer 35 and a second planarization layer 36, the first planarization layer 35 covers the color resist layer 32 and the black matrix 31, the first bias electrode 33 and the second bias electrode 34 are formed on the first planarization layer 35, the first bias electrode 33 and the second bias electrode 34 can be formed by etching and patterning the same transparent conductive layer, and the second planarization layer 36 covers the first bias electrode 33 and the second bias electrode 34.

The first bias electrode 33, the second bias electrode 34, the common electrode 25 and the pixel electrode 24 may be made of a transparent conductive material such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO). The first bias electrode 33 and the second bias electrode 34 are used for applying voltage signals to realize the wide and narrow viewing angle switching of the liquid crystal display device, the common electrode 25 is used for applying a common voltage (Vcom) for displaying pictures, and the pixel electrode 24 is used for receiving a driving voltage (Vdata) through the data line 22 to realize different gray scale display of the pictures.

In this embodiment, the liquid crystal molecules in the liquid crystal layer 40 are positive liquid crystal molecules, and the positive liquid crystal molecules have the advantage of fast response. As shown in fig. 5, in the initial state, the positive liquid crystal molecules in the liquid crystal layer 40 assume a lying posture substantially parallel to the

substrates

20, 30, that is, the long axis direction of the positive liquid crystal molecules is substantially parallel to the surfaces of the

substrates

20, 30. In practical applications, however, the positive liquid crystal molecules in the liquid crystal layer 40 and the

substrates

20 and 30 may have a small initial pretilt angle, which may range from 10 degrees or less, that is: 0 DEG ≦ theta ≦ 10 deg.

The first bias electrode 33 and the second bias electrode 34 of the upper substrate 30 are used to control the liquid crystal display device to switch between a wide viewing angle mode and a narrow viewing angle mode, and by applying different voltage signals to the first bias electrode 33 and the second bias electrode 34, different voltage differences (i.e., bias voltages) can be generated between the first bias electrode 33 and the pixel electrode 24 and the common electrode 25 and between the second bias electrode 34 and the pixel electrode 24 and the common electrode 25 to control the liquid crystal display device to switch between the wide viewing angle mode and the narrow viewing angle mode.

Wide view angle mode: referring to fig. 5, in the wide viewing angle mode, a direct current common voltage (DC Vcom), which may be 0V, is applied to the common electrode 25; outputting a driving voltage (Vdata) to each pixel electrode 24 of the lower substrate 20 and implementing gray scale display (e.g., darkest is L0 gray scale and corresponding to 0V, brightest is L255 gray scale and corresponding to 5V) by different voltage values; voltage signals are respectively applied to the first bias electrode 33 and the second bias electrode 34 of the upper substrate 30, so that the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are both smaller than a predetermined value (e.g., smaller than 1V). At this time, since the voltage difference between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 is small, the tilt angle of the liquid crystal molecules in the liquid crystal layer 40 hardly changes, and the liquid crystal display device is maintained in a nearly flat posture, so that the liquid crystal display device realizes normal wide viewing angle display.

In the wide viewing angle mode, it is preferable that the same direct current voltage signal as the direct current common voltage (DC Vcom) of the common electrode 25 is applied to both the first bias electrode 33 and the second bias electrode 34, so that the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are all zero.

In other embodiments, in the wide viewing angle mode, an ac voltage signal may be applied to both the first bias electrode 33 and the second bias electrode 34, as long as it is ensured that the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are both less than a predetermined value (e.g., less than 1V).

Narrow view angle mode: referring to fig. 6 and 7, in the narrow viewing angle mode, a direct current common voltage (DC Vcom), which may be 0V, is applied to the common electrode 25; outputting a driving voltage (Vdata) to each pixel electrode 24 of the lower substrate 20 and implementing gray scale display (e.g., darkest is L0 gray scale and corresponding to 0V, brightest is L255 gray scale and corresponding to 5V) by different voltage values; a first ac voltage (CF ITO 1) is applied to the first bias electrode 33 of the upper substrate 30, and a second ac voltage (CF ITO 2) is applied to the second bias electrode 34 of the upper substrate 30, so that the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are both greater than a predetermined value (e.g., greater than 3V). At this time, due to the large voltage difference between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25, a strong vertical electric field E (as shown by the arrow in fig. 6) is generated between the lower substrate 20 and the upper substrate 30 in the liquid crystal cell, and the positive liquid crystal molecules rotate in the direction parallel to the electric field lines under the action of the electric field, so that the positive liquid crystal molecules deflect under the action of the vertical electric field E, the tilt angle between the liquid crystal molecules and the

substrates

20 and 30 is increased and tilted, the liquid crystal molecules are changed from the lying posture to the tilting posture, the liquid crystal display device has large-angle observation light leakage, the contrast is reduced and the viewing angle is narrowed in the tilting direction, and the liquid crystal display device finally realizes narrow viewing angle display.

Preferably, in the narrow viewing angle mode, the first alternating voltage applied to the first bias electrode 33 and the second alternating voltage applied to the second bias electrode 34 have the same potential symmetry center as the direct current common voltage (DC Vcom) potential of the common electrode 25, that is, the first alternating voltage and the second alternating voltage both fluctuate around the DC Vcom, and have the same potential difference with respect to the common electrode 25.

In the narrow viewing angle mode, the pixel units covered by each first electrode strip 331 of the first bias electrode 33 and the pixel units covered by each second electrode strip 341 of the second bias electrode 34 have alternating positive and negative polarities. In the embodiment, in the narrow viewing angle mode, the polarities of the driving voltages output to the pixel units are in column inversion, that is, the polarity of the pixel unit in the K +1 th column of the lower substrate 20 is opposite to the polarity of the pixel unit in the K +2 th column and the adjacent pixel unit in the K +1 th column (K ≧ 1), and the pixel units in each row are arranged in an alternating positive and negative different polarity. Since each of the first electrode stripes 331 and each of the second electrode stripes 341 extend along the horizontal direction and each cover one row of pixel units in the present embodiment, the pixel units in the row covered by each of the first electrode stripes 331 exhibit alternating positive and negative polarities, and the pixel units in the row covered by each of the second electrode stripes 341 exhibit alternating positive and negative polarities.

In the embodiment, in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are both 1/2 of the frame frequency of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes two frames (frames) of the picture, and the polarity of the driving voltage output to each pixel unit is inverted every two frames of the picture, that is, the display polarity of the N +1 th frame is the same as that of the N +2 th frame, the polarity of the N +3 th frame is inverted, and the display polarity of the N +4 th frame is the same as that of the N +3 th frame (N ≧ 0).

Further, in the present embodiment, in the narrow viewing angle mode, the first alternating voltage applied to the first bias electrode 33 and the second alternating voltage applied to the second bias electrode 34 have opposite polarities with respect to the direct current common voltage (DC Vcom) on the common electrode 25. In this embodiment, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 are both square waves and mirror images with respect to the DC common voltage (DC Vcom) on the common electrode 25, i.e. the first ac voltage and the second ac voltage are positive and negative with respect to the DC Vcom in the same frame. In addition, the polarity of the first alternating voltage is opposite to that of the adjacent two frames of pictures, and the polarity of the second alternating voltage is also opposite to that of the adjacent two frames of pictures, namely, the polarity of the first alternating voltage and the polarity of the second alternating voltage are changed once every two adjacent frames of pictures are switched. Specifically, a blanking time (blanking time) may be provided between two adjacent frames, and the positive and negative polarities of the first ac voltage and the second ac voltage may be switched in the blanking time.

Since each pixel cell covered by each first electrode stripe 331 of the first bias electrode 33 has alternating positive and negative different polarities, and each pixel cell covered by each second electrode stripe 341 of the second bias electrode 34 also has alternating positive and negative different polarities, the display effect of the adjacent pixel cells is bright and dark under the pressure difference formed by the interaction of the pixel cells with positive polarity and negative polarity in the same row with the first bias electrode 33 or the second bias electrode 34. Taking an ac square wave with the first ac voltage and the second ac voltage as the amplitude of 5V, taking the maximum voltage applied to each pixel electrode 24 of the display panel 10 when displaying a white picture as 5V (+ 5V in the case of positive polarity and-5V in the case of negative polarity) as an example, please refer to fig. 7 and 8, where the value in each pixel cell in fig. 8 represents the voltage difference between the first bias electrode 33, the second bias electrode 34 and each pixel electrode 24 in different frame pictures, as can be seen from the figure, the voltage difference between each first electrode stripe 331 and each pixel electrode 24 correspondingly covered therewith changes between 0V and 10V, and similarly, the voltage difference between each second electrode stripe 341 and each pixel electrode 24 correspondingly covered therewith also changes between 0V and 10V, and the high-low voltage difference in the adjacent upper and lower rows is also distributed in a staggered manner.

For the same row of pixel units, although the pixel units in the row are all positive or negative, because they act on the first bias electrode 33 and the second bias electrode 34 simultaneously, the pixel units in the row display the effect that the adjacent pixel units are bright and dark, and the pixel units in the same row are alternately arranged in turn, rather than the phenomenon that the pixel units in the entire row are bright or the pixel units in the entire row are dark, which occurs in the conventional architecture. For two adjacent columns of pixel units, the pixel unit appearance in the two adjacent columns of pixel units is also reflected by the brightness difference. For all pixel units in the whole picture, other pixel units adjacent to the brighter pixel unit are relatively darker pixel units, and other pixel units adjacent to the darker pixel unit are relatively brighter. Therefore, the problem of dark lines formed by pixel units concentrated in the same column and dark relative to adjacent columns, namely the phenomenon of vertical stripe abnormality arranged along the column direction in a macroscopic manner, cannot exist in the conventional framework that all the pixel units in the same column are always bright or dark.

In the narrow viewing angle mode, the waveform of the periodic ac voltage applied to the first and

second bias electrodes

33 and 34 may be a square wave, a sine wave, a triangular wave, or a sawtooth wave.

As shown in fig. 5 and 6, the liquid crystal display device further includes a driving circuit 50, and the driving circuit 50 applies a desired voltage signal to the first bias electrode 33 and the second bias electrode 34, respectively. In order to apply voltage signals to the first bias electrode 33 and the second bias electrode 34 of the upper substrate 30, the lower substrate 20 may be connected to the upper substrate 30 through the conductive paste 60 in the peripheral non-display region of the display panel 10, the driving circuit 50 provides the voltage signals to the lower substrate 20, and the lower substrate 20 applies the voltage signals to the first bias electrode 33 and the second bias electrode 34 of the upper substrate 30 through the conductive paste 60.

Further, the second planarization layer 36 may be formed with a through hole (not shown) in the peripheral non-display area to expose the first bias electrode 33 or the second bias electrode 34, so that the conductive paste 60 is electrically connected to the first bias electrode 33 or the second bias electrode 34 through the corresponding through hole.

The driving method of the liquid crystal display device with switchable wide and narrow viewing angles provided by this embodiment can realize the switching of two modes of wide and narrow viewing angles by the arrangement mode and the signal application of the bias electrode of the upper substrate in combination with the inversion driving mode of the lower substrate, and simultaneously solve the problems of vertical stripes and horizontal stripes in the conventional framework, thereby improving the display image quality of the display device.

It should be noted that, in the wide viewing angle mode of normal display, the polarity inversion method of the driving voltage output to each pixel unit in the present embodiment is not limited, and may adopt column inversion, row inversion or dot inversion, and may adopt polarity inversion once per frame or once per two frames.

[ second embodiment ]

Referring to fig. 9 and 10, the difference between the present embodiment and the first embodiment is that in the present embodiment, the plurality of first electrode stripes 331 of the first bias electrodes 33 and the plurality of second electrode stripes 341 of the second bias electrodes 34 all extend along the vertical direction, that is, all extend along the data lines 22. The first electrode stripes 331 respectively cover the pixel cells in the odd columns (i.e., 1 st, 3 rd, 5 th, … …), and the second electrode stripes 341 respectively cover the pixel cells in the even columns (i.e., 2 nd, 4 th, 6 th, … …).

As shown in FIG. 10, in the narrow viewing angle mode, the polarity of the driving voltage outputted to each pixel unit is reversed by row, the polarity of the pixel unit in the K +1 th row of the lower substrate 20 is opposite to the polarity of the pixel unit in the adjacent K +2 th row (K ≧ 1), and each pixel unit in each column is arranged in an alternating positive and negative different polarity. Since each of the first electrode stripes 331 and each of the second electrode stripes 341 extend along the vertical direction and each cover one column of pixel units in the present embodiment, each of the pixel units in one column covered by each of the first electrode stripes 331 exhibits alternating positive and negative different polarities, and each of the pixel units in one column covered by each of the second electrode stripes 341 exhibits alternating positive and negative different polarities.

In the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are both 1/2 of the frame rate of the liquid crystal display device, and the polarity of the driving voltage output to each pixel unit is inverted every two frames.

Since each pixel cell covered by each first electrode stripe 331 of the first bias electrode 33 has alternating positive and negative different polarities, and each pixel cell covered by each second electrode stripe 341 of the second bias electrode 34 also has alternating positive and negative different polarities, the display effect of the adjacent pixel cells is bright and dark under the pressure difference formed by the interaction of the pixel cells with positive polarity and negative polarity in the same column with the first bias electrode 33 or the second bias electrode 34.

For the same row of pixel units, although the row of pixel units all display positive polarity or negative polarity, since they act on the first bias electrode 33 and the second bias electrode 34 simultaneously, the effect of the row of pixel units is that the adjacent pixel units are bright and dark, and the pixel units in the same row are alternately arranged in turn, rather than the phenomenon that the pixel units in the whole row are bright or the pixel units in the whole row are dark as in the conventional architecture. For two adjacent rows of pixel units, the pixel unit appearance in the two adjacent rows of pixel units is also reflected as a brightness difference. For all pixel units in the whole picture, other pixel units adjacent to the brighter pixel unit are relatively darker pixel units, and other pixel units adjacent to the darker pixel unit are relatively brighter. Therefore, the problem of dark lines formed by pixel units concentrated in the same row and dark relative to adjacent rows, namely the phenomenon of cross striation which is macroscopically arranged along the row direction, cannot exist in the traditional framework that all the pixel units in the same row are always bright or dark.

The rest of the present embodiment can refer to the description of the first embodiment, and is not repeated herein.

[ third embodiment ]

Referring to fig. 11, the difference between the present embodiment and the first embodiment is that in the narrow viewing angle mode, the polarities of the driving voltages output to the pixel units are in dot inversion, and the polarity of any one pixel unit is opposite to the polarities of all other adjacent pixel units, so that the pixel units in a row covered by each first electrode strip 331 exhibit alternating positive and negative polarities, and the pixel units in a row covered by each second electrode strip 341 exhibit alternating positive and negative polarities.

In the narrow viewing angle mode, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 have the same polarity with respect to the DC common voltage (DC Vcom) on the common electrode 25. In this embodiment, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 are both square waves and have the same waveform, that is, within the same frame, both the first ac voltage and the second ac voltage are positive or both negative with respect to DC Vcom.

Since each pixel cell covered by each first electrode stripe 331 of the first bias electrode 33 has alternating positive and negative different polarities, and each pixel cell covered by each second electrode stripe 341 of the second bias electrode 34 also has alternating positive and negative different polarities, the display effect of the adjacent pixel cells is bright and dark under the pressure difference formed by the interaction of the pixel cells with positive polarity and negative polarity in the same row with the first bias electrode 33 or the second bias electrode 34. For all pixel units in the whole picture, other pixel units adjacent to the brighter pixel unit are relatively darker pixel units, and other pixel units adjacent to the darker pixel unit are relatively brighter. Therefore, the problem of dark lines formed by pixel units concentrated in the same column and dark relative to adjacent columns, namely the phenomenon of vertical stripe abnormality arranged along the column direction in a macroscopic manner, cannot exist in the conventional framework that all the pixel units in the same column are always bright or dark.

[ fourth embodiment ]

Referring to fig. 12, the difference between the present embodiment and the first embodiment is that in the present embodiment, the plurality of first electrode stripes 331 of the first bias electrodes 33 and the plurality of second electrode stripes 341 of the second bias electrodes 34 all extend along the vertical direction, that is, all extend along the data lines 22. The first electrode stripes 331 respectively cover the pixel cells in the odd columns (i.e., 1 st, 3 rd, 5 th, … …), and the second electrode stripes 341 respectively cover the pixel cells in the even columns (i.e., 2 nd, 4 th, 6 th, … …).

In the narrow viewing angle mode, the polarity of the driving voltage output to each pixel unit is dot-inverted, and the polarity of any pixel unit is opposite to the polarity of all other pixel units adjacent to the pixel unit, so that each pixel unit in a column covered by each first electrode strip 331 exhibits alternating positive and negative different polarities, and each pixel unit in a column covered by each second electrode strip 341 exhibits alternating positive and negative different polarities.

Since each pixel cell covered by each first electrode stripe 331 of the first bias electrode 33 has alternating positive and negative different polarities, and each pixel cell covered by each second electrode stripe 341 of the second bias electrode 34 also has alternating positive and negative different polarities, the display effect of the adjacent pixel cells is bright and dark under the pressure difference formed by the interaction of the pixel cells with positive polarity and negative polarity in the same column with the first bias electrode 33 or the second bias electrode 34. For all pixel units in the whole picture, other pixel units adjacent to the brighter pixel unit are relatively darker pixel units, and other pixel units adjacent to the darker pixel unit are relatively brighter. Therefore, the problem of dark lines formed by pixel units concentrated in the same row and dark relative to adjacent rows, namely the phenomenon of cross striation which is macroscopically arranged along the row direction, cannot exist in the traditional framework that all the pixel units in the same row are always bright or dark.

[ fifth embodiment ]

Referring to fig. 13, the difference between the present embodiment and the first embodiment is that in the narrow viewing angle mode, the polarity of the driving voltage outputted to each pixel unit is in a DOT inversion manner (i.e. 2DOT inversion) with two adjacent pixel units as a group, and the polarities of the two adjacent pixel units are the same and are opposite to the polarities of all other adjacent pixel units, so that each pixel unit in a row covered by each first electrode stripe 331 exhibits alternating positive and negative polarities, and each pixel unit in a row covered by each second electrode stripe 341 exhibits alternating positive and negative polarities.

In the narrow viewing angle mode, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 have the same polarity with respect to the DC common voltage (DC Vcom) on the common electrode 25.

For the rest of the contents and principles of this embodiment, reference may be made to the descriptions of the first embodiment and the third embodiment, which are not repeated herein.

[ sixth embodiment ]

Referring to fig. 14, the difference between the present embodiment and the first embodiment is that in the present embodiment, the plurality of first electrode stripes 331 of the first bias electrodes 33 and the plurality of second electrode stripes 341 of the second bias electrodes 34 all extend along the vertical direction, that is, all extend along the data lines 22. The first electrode stripes 331 respectively cover the pixel cells in the odd columns (i.e., 1 st, 3 rd, 5 th, … …), and the second electrode stripes 341 respectively cover the pixel cells in the even columns (i.e., 2 nd, 4 th, 6 th, … …).

In the embodiment, in the narrow viewing angle mode, the polarity of the driving voltage outputted to each pixel unit is in a DOT inversion manner (i.e. 2DOT inversion) with two adjacent pixel units as a group, and the polarities of the two adjacent pixel units are the same and are opposite to the polarities of all other adjacent pixel units, so that each pixel unit in a column covered by each first electrode stripe 331 exhibits alternating positive and negative different polarities, and each pixel unit in a column covered by each second electrode stripe 341 exhibits alternating positive and negative different polarities.

For the rest of the contents and principles of this embodiment, reference may be made to the descriptions of the first embodiment and the fourth embodiment, which are not repeated herein.

[ seventh embodiment ]

Referring to fig. 15, the driving method of the present embodiment is different from that of the first embodiment (see fig. 7) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame rate of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted every four frames of pictures, i.e., the display polarities of the N +1 th frame, the N +2 th frame, the N +3 th frame and the N +4 th frame are the same, the polarity inversion is carried out on the (N + 5) th frame, and the display polarities of the (N + 8) th frame, the (N + 7) th frame, the (N + 6) th frame and the (N + 5) th frame are the same (N is more than or equal to 0).

In the narrow viewing angle mode, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 have opposite polarities with respect to the DC common voltage (DC Vcom) on the common electrode 25 in the present embodiment. Specifically, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 are both square waves and mirror images with respect to the DC common voltage (DC Vcom) on the common electrode 25.

In the embodiment, in the narrow viewing angle mode, the polarities of the driving voltages output to the pixel units are matched to adopt a column inversion mode, so that the problem that all the pixel units in the same column of the conventional architecture are always slightly bright or dark, and a dark line is formed by the pixel units which are concentrated in the same column and are slightly dark relative to the adjacent column, namely, the phenomenon of abnormal vertical stripes which are macroscopically arranged along the column direction can be avoided.

[ eighth embodiment ]

Referring to fig. 16, the driving method of the present embodiment is different from that of the second embodiment (see fig. 10) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame rate of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted every four frames of pictures, i.e., the display polarities of the N +1 th frame, the N +2 th frame, the N +3 th frame and the N +4 th frame are the same, the polarity inversion is carried out on the (N + 5) th frame, and the display polarities of the (N + 8) th frame, the (N + 7) th frame, the (N + 6) th frame and the (N + 5) th frame are the same (N is more than or equal to 0).

In the embodiment, in the narrow viewing angle mode, the polarity of the driving voltage output to each pixel unit is matched to adopt a row inversion mode, so that the problem that all the pixel units in the same row of the traditional architecture are always slightly bright or dark, and a dark line is formed by the pixel units which are concentrated in the same row and are slightly dark relative to the adjacent row, namely, the macro cross striation abnormal phenomenon arranged along the row direction can be avoided.

[ ninth embodiment ]

Referring to fig. 17, the driving method of the present embodiment is different from that of the third embodiment (see fig. 11) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame rate of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted every four frames of pictures, i.e., the display polarities of the N +1 th frame, the N +2 th frame, the N +3 th frame and the N +4 th frame are the same, the polarity inversion is carried out on the (N + 5) th frame, and the display polarities of the (N + 8) th frame, the (N + 7) th frame, the (N + 6) th frame and the (N + 5) th frame are the same (N is more than or equal to 0).

In the narrow viewing angle mode, the first ac voltage applied to the first bias electrode 33 and the second ac voltage applied to the second bias electrode 34 have the same polarity with respect to the DC common voltage (DC Vcom) on the common electrode 25. Specifically, the first alternating voltage applied to the first bias electrode 33 and the second alternating voltage applied to the second bias electrode 34 are both square waves and have the same waveform.

In the embodiment, in the narrow viewing angle mode, the polarities of the driving voltages output to the pixel units are matched to adopt a dot inversion method, so that the problem that all the pixel units in the same column of the conventional architecture are always slightly bright or dark, and a dark line is formed by the pixel units which are concentrated in the same column and are slightly dark relative to the adjacent column, namely, the phenomenon of abnormal vertical stripes which are macroscopically arranged along the column direction can be avoided.

[ tenth embodiment ]

Referring to fig. 18, the driving method of the present embodiment is different from that of the fourth embodiment (see fig. 12) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame rate of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted every four frames of pictures, i.e., the display polarities of the N +1 th frame, the N +2 th frame, the N +3 th frame and the N +4 th frame are the same, the polarity inversion is carried out on the (N + 5) th frame, and the display polarities of the (N + 8) th frame, the (N + 7) th frame, the (N + 6) th frame and the (N + 5) th frame are the same (N is more than or equal to 0).

In the embodiment, in the narrow viewing angle mode, the polarities of the driving voltages output to the pixel units are matched in a dot inversion manner, so that the problem of dark lines formed by the pixel units which are concentrated in the same row and are relatively dark to adjacent rows, namely the phenomenon of cross striation abnormality macroscopically arranged along the row direction, can be solved.

[ eleventh embodiment ]

Referring to fig. 19, the driving method of the present embodiment is different from that of the first embodiment (see fig. 7) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame frequency of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted once per frame of pictures, that is, the polarity of each pixel unit is different between two adjacent frames of pictures.

[ twelfth embodiment ]

Referring to fig. 20, the driving method of the present embodiment is different from that of the second embodiment (see fig. 10) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame frequency of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted once per frame of pictures, that is, the polarity of each pixel unit is different between two adjacent frames of pictures.

[ thirteenth embodiment ]

Referring to fig. 21, the driving method of the present embodiment is different from that of the third embodiment (see fig. 11) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame frequency of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted once per frame of pictures, that is, the polarity of each pixel unit is different between two adjacent frames of pictures.

[ fourteenth embodiment ]

Referring to fig. 22, the driving method of the present embodiment is different from that of the fourth embodiment (see fig. 12) in that in the narrow viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode 33 and the driving frequency of the second ac voltage applied to the second bias electrode 34 are 1/4 of the frame frequency of the liquid crystal display device, that is, in one period T of the first ac voltage and the second ac voltage, the display panel 10 refreshes four frames (frames) of pictures, and the polarity of the driving voltage output to each pixel unit is inverted once per frame of pictures, that is, the polarity of each pixel unit is different between two adjacent frames of pictures.

[ fifteenth embodiment ]

When the first bias electrode 33 and the second bias electrode 34 are made of a transparent conductive material such as ITO or IZO, the waveforms of the voltages transmitted by the first bias electrode 33 and the second bias electrode 34 are easily distorted and signal delay is generated due to the large impedance and load of ITO or IZO. As shown in fig. 23, the upper substrate 30 is further provided with a plurality of first metal strips 37 and a plurality of second metal strips 38, the plurality of first metal strips 37 are parallel to the plurality of first electrode strips 331 and are respectively in conductive connection with the plurality of first electrode strips 331, and the plurality of second metal strips 38 are parallel to the plurality of second electrode strips 341 and are respectively in conductive connection with the plurality of second electrode strips 341.

The plurality of first metal strips 37 and the plurality of second metal strips 38 may be made of a metal having a low resistivity, such as Mo, Al, Au, Ag, Cu, or the like. These metal strips 37, 38 correspond to the positions of the black matrix 31, and each metal strip 37 (or 38) can be electrically connected to the electrode strip 331 (or 341) corresponding to the opening area by partial contact.

By arranging the first metal strip 37 and the second metal strip 38 which are respectively in conductive connection with the first bias electrode 33 and the second bias electrode 34, the resistances of the metal strips 37 and 38 are small, the conducting capability is strong, and the impedances and loads of the first bias electrode 33 and the second bias electrode 34 are greatly reduced, so that the problem of signal delay on the first bias electrode 33 and the second bias electrode 34 is solved, the waveform distortion phenomenon can be reduced, and the display image quality is prevented from being abnormal due to waveform distortion or signal attenuation.

In the present embodiment, the metal strips 37 and 38 and the first and second electrode strips 331 and 341 extend along a vertical direction, i.e., along the direction of the data line 22.

The specific positions of the metal strips 37 and 38 on the upper substrate 30 are not limited, and can be adjusted according to the needs, as shown in fig. 24a to 24 d.

As shown in fig. 24a, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first planarization layer 35, a first metal stripe 37, a second metal stripe 38, a first bias electrode 33, a second bias electrode 34, and a second planarization layer 36 on a side facing the liquid crystal layer 40. The first flat layer 35 covers the black matrix 31 and the color resist layer 32, then the first metal strip 37, the second metal strip 38, the first bias electrode 33, and the second bias electrode 34 are sequentially formed on the first flat layer 35, and then the second flat layer 36 covers the first metal strip 37, the second metal strip 38, the first bias electrode 33, and the second bias electrode 34.

As shown in fig. 24b, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first planarization layer 35, a first bias electrode 33, a second bias electrode 34, a first metal stripe 37, a second metal stripe 38, and a second planarization layer 36 on a side facing the liquid crystal layer 40. The first flat layer 35 covers the black matrix 31 and the color resist layer 32, then the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are sequentially formed on the first flat layer 35, and then the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are sequentially covered by the second flat layer 36.

As shown in fig. 24c, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first bias electrode 33, a second bias electrode 34, a first metal strip 37, a second metal strip 38, and a planarization layer 39 on a side facing the liquid crystal layer 40. A first bias electrode 33, a second bias electrode 34, a first metal strip 37 and a second metal strip 38 are formed on the black matrix 31 and the color resist layer 32, and the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are covered with a planarization layer 39.

As shown in fig. 24d, the upper substrate 30 is provided with a black metal, a color resist layer 32, a first bias electrode 33, a second bias electrode 34, and a planarization layer 39 on the side facing the liquid crystal layer 40. The first metal strip 37 and the second metal strip 38 are made of ferrous metal, and the first metal strip 37 and the second metal strip 38 are used as a Black Matrix (BM) in the vertical direction, so that the manufacturing steps and the cost of the original Black Matrix (BM) are saved. A first bias electrode 33 and a second bias electrode 34 are formed on the black metal and color resist layer 32, and the first bias electrode 33, the second bias electrode 34 and the black metal are covered with a planarization layer 39.

[ sixteenth embodiment ]

As shown in fig. 25, in the present embodiment, the upper substrate 30 is further provided with a plurality of first metal strips 37 and a plurality of second metal strips 38, the plurality of first metal strips 37 are parallel to the plurality of first electrode strips 331 and are respectively in conductive connection with the plurality of first electrode strips 331, and the plurality of second metal strips 38 are parallel to the plurality of second electrode strips 341 and are respectively in conductive connection with the plurality of second electrode strips 341.

In the present embodiment, the metal strips 37 and 38 and the first electrode strips 331 and the second electrode strips 341 extend along the horizontal direction, i.e., along the direction of the scan line 21.

The specific positions of the metal strips 37 and 38 on the upper substrate 30 are not limited, and can be adjusted according to the needs, as shown in fig. 26a to 26 d.

As shown in fig. 26a, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first planarization layer 35, a first metal stripe 37, a second metal stripe 38, a first bias electrode 33, a second bias electrode 34, and a second planarization layer 36 on a side facing the liquid crystal layer 40. The first flat layer 35 covers the black matrix 31 and the color resist layer 32, then the first metal strip 37, the second metal strip 38, the first bias electrode 33, and the second bias electrode 34 are sequentially formed on the first flat layer 35, and then the second flat layer 36 covers the first metal strip 37, the second metal strip 38, the first bias electrode 33, and the second bias electrode 34.

As shown in fig. 26b, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first planarization layer 35, a first bias electrode 33, a second bias electrode 34, a first metal stripe 37, a second metal stripe 38, and a second planarization layer 36 on a side facing the liquid crystal layer 40. The first flat layer 35 covers the black matrix 31 and the color resist layer 32, then the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are sequentially formed on the first flat layer 35, and then the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are sequentially covered by the second flat layer 36.

As shown in fig. 26c, the upper substrate 30 is provided with a black matrix 31, a color resist layer 32, a first bias electrode 33, a second bias electrode 34, a first metal strip 37, a second metal strip 38, and a planarization layer 39 on a side facing the liquid crystal layer 40. A first bias electrode 33, a second bias electrode 34, a first metal strip 37 and a second metal strip 38 are formed on the black matrix 31 and the color resist layer 32, and the first bias electrode 33, the second bias electrode 34, the first metal strip 37 and the second metal strip 38 are covered with a planarization layer 39.

As shown in fig. 26d, the upper substrate 30 is provided with a black metal, a color resist layer 32, a first bias electrode 33, a second bias electrode 34, and a planarization layer 39 on the side facing the liquid crystal layer 40. The first metal strip 37 and the second metal strip 38 are made of ferrous metal, and the first metal strip 37 and the second metal strip 38 are used as a Black Matrix (BM) in the horizontal direction, so that the manufacturing steps and cost of the original Black Matrix (BM) are saved. A first bias electrode 33 and a second bias electrode 34 are formed on the black metal and color resist layer 32, and the first bias electrode 33, the second bias electrode 34 and the black metal are covered with a planarization layer 39.

[ seventeenth embodiment ]

Referring to fig. 27 and 28, the difference between the liquid crystal display device of the present embodiment and the first embodiment is that the liquid crystal layer 40 of the present embodiment uses negative liquid crystal molecules. With the technical progress, the performance of the negative liquid crystal is remarkably improved, and the application is more and more extensive. In the present embodiment, as shown in fig. 27, in the initial state, the negative liquid crystal molecules in the liquid crystal layer 40 have a large initial pretilt angle with respect to the

substrates

20 and 30, that is, the negative liquid crystal molecules are in an inclined posture with respect to the

substrates

20 and 30 in the initial state.

Narrow view angle mode: referring to fig. 27, in the embodiment, when the voltage differences applied between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are both smaller than a predetermined value (e.g., smaller than 1V), since the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are smaller, the tilt angle of the liquid crystal molecules in the liquid crystal layer 40 is almost not changed, and is still kept in a tilt posture, so that the liquid crystal display device has large-angle viewing light leakage, and the contrast ratio is reduced and the viewing angle is narrowed in the oblique viewing direction, and at this time, the liquid crystal display device realizes narrow viewing angle display. Namely: the driving manner of the present embodiment in the narrow viewing angle mode corresponds to the same manner as the driving manner of the first embodiment in the wide viewing angle mode.

Wide view angle mode: referring to fig. 28, in the embodiment, when a first ac voltage is applied to the first bias electrode 33 and a second ac voltage is applied to the second bias electrode 34, and the voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25 are both greater than a predetermined value (e.g., greater than 3V), a strong vertical electric field E (as shown by an arrow in fig. 28) is generated between the lower substrate 20 and the upper substrate 30 in the liquid crystal cell due to the large voltage differences between the first bias electrode 33 and the common electrode 25 and between the second bias electrode 34 and the common electrode 25, and negative liquid crystal molecules are deflected in a direction perpendicular to electric field lines under the action of the electric field, so that the tilt angle between the liquid crystal molecules and the

substrates

20 and 30 is reduced, and the large-angle light leakage phenomenon of the liquid crystal display device is correspondingly reduced, the contrast ratio is improved and the visual angle is increased in the oblique viewing direction, and the liquid crystal display device finally realizes wide visual angle display. Namely: the driving manner of the present embodiment in the wide viewing angle mode corresponds to the same manner as the driving manner of the first embodiment in the narrow viewing angle mode.

Other structures and principles of this embodiment can be seen in the above embodiments, and are not described herein again.

[ eighteenth embodiment ]

Referring to fig. 29a and 29b, in order to switch the wide and narrow viewing angles, a viewing angle switching key 80 is further provided for switching different viewing angle modes of the liquid crystal display device. The viewing angle switching key 80 may be a mechanical key (as shown in fig. 29a) or a virtual key (as shown in fig. 29b, set by software control or an application program). When a user needs to switch the wide and narrow viewing angles, the viewing angle switching key 80 can be operated to send a viewing angle switching request to the liquid crystal display device, and finally the driving circuit 50 controls the voltage signals applied to the first bias electrode 33 and the second bias electrode 34 of the upper substrate 30 and controls the inversion driving mode of the lower substrate 20 to realize the switching of the wide and narrow viewing angles, so that the user can freely select and switch the wide and narrow viewing angles according to different peep-proof requirements, and therefore the liquid crystal display device has strong operation flexibility and convenience.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Industrial applicability

The driving method provided by the embodiment of the invention can realize the switching of two modes of wide and narrow visual angles by the arrangement mode and the signal application of the bias electrode of the upper substrate and the inversion driving mode of the lower substrate, simultaneously solves the problems of vertical stripes and horizontal stripes in the traditional framework and improves the display image quality of the display device.

Claims

1. A driving method of a liquid crystal display device with switchable wide and narrow viewing angles, the liquid crystal display device comprises a lower substrate, an upper substrate and a liquid crystal layer positioned between the lower substrate and the upper substrate; the lower substrate is provided with a scanning line, a data line, a pixel electrode and a common electrode, and a plurality of pixel units are formed by mutually insulating, crossing and limiting a plurality of scanning lines and a plurality of data lines; the upper substrate is provided with a first bias electrode and a second bias electrode, the first bias electrode comprises a plurality of first electrode strips which are electrically connected together, the second bias electrode comprises a plurality of second electrode strips which are electrically connected together, and the plurality of first electrode strips and the plurality of second electrode strips are mutually inserted and matched in an interdigital shape, and the driving method is characterized by comprising the following steps:

in a second viewing angle mode, the polarities of the driving voltages output to the pixel units are inverted in a row manner, the first alternating voltage applied to the first bias electrode and the second alternating voltage applied to the second bias electrode have opposite polarities relative to the direct-current common voltage on the common electrode, adjacent pixel units in the same row are represented by bright and dark, other pixel units adjacent to the brighter pixel unit are represented by relatively dark, and other pixel units adjacent to the darker pixel unit are represented by relatively bright and dark; or, the plurality of first electrode stripes and the plurality of second electrode stripes extend along the vertical direction, in the second viewing angle mode, the polarity of the driving voltage output to each pixel unit is inverted by a line, the first alternating voltage applied to the first bias electrode and the second alternating voltage applied to the second bias electrode have opposite polarity relative to the direct current common voltage on the common electrode, the adjacent pixel units in the same line are represented by bright and dark, other pixel units adjacent to the brighter pixel unit are represented by relatively dark, and other pixel units adjacent to the darker pixel unit are represented by relatively bright.

2. The driving method according to claim 1, wherein when the polarity of the driving voltage outputted to each pixel unit is column-inverted or row-inverted, in the second viewing angle mode, the first ac voltage applied to the first bias electrode and the second ac voltage applied to the second bias electrode are both square waves and mirror images with respect to the dc common voltage on the common electrode.

3. The driving method according to claim 1, wherein in the second viewing angle mode, the driving frequency of the first ac voltage applied to the first bias electrode and the driving frequency of the second ac voltage applied to the second bias electrode are both 1/2 of the frame rate of the lcd device, and the polarity of the driving voltage output to each pixel unit is inverted every two frames.

4. The driving method according to claim 1, wherein in the second viewing angle mode, the driving frequency of the first AC voltage applied to the first bias electrode and the driving frequency of the second AC voltage applied to the second bias electrode are 1/4 of the frame rate of the LCD device, and the polarity of the driving voltage output to each pixel unit is inverted once per frame or once per four frames.

5. The driving method according to claim 1, wherein in the first viewing angle mode, a dc voltage signal equal to the dc common voltage of the common electrode is applied to both the first bias electrode and the second bias electrode, such that the voltage difference between the first bias electrode and the common electrode and between the second bias electrode and the common electrode is zero.

6. The driving method as claimed in claim 1, wherein the liquid crystal layer uses positive liquid crystal molecules, the first viewing angle mode is a wide viewing angle mode, and the second viewing angle mode is a narrow viewing angle mode.

7. The driving method as claimed in claim 1, wherein the liquid crystal layer uses negative liquid crystal molecules, the first viewing angle mode is a narrow viewing angle mode, and the second viewing angle mode is a wide viewing angle mode.

8. The driving method as claimed in claim 1, wherein the upper substrate is further provided with a plurality of first metal strips and a plurality of second metal strips, the plurality of first metal strips are parallel to the plurality of first electrode strips and are respectively and electrically connected to the plurality of first electrode strips, and the plurality of second metal strips are parallel to the plurality of second electrode strips and are respectively and electrically connected to the plurality of second electrode strips.

9. The driving method as claimed in claim 1, wherein the LCD device is provided with a viewing angle switching key for switching different viewing angle modes of the LCD device.